Parts for your 2011 Ford Focus-Camshaft sensor

2011 Ford Focus camshaft sensor: what it does and when to sort it

Drawing on technical references such as the Ford Workshop Manual for Focus (Section 303 – Engine, and 303-14 – Electronic Engine Controls) and common service data used by Motorcraft and Autodata, the 2011 Ford Focus is fitted with a camshaft position sensor (often called a CMP). Depending on engine variant (1.6 Ti‑VCT petrol, 2.0 GDI petrol, or TDCi diesel), there’s at least one CMP and in some cases two (intake and exhaust) to support Twin Independent Variable Camshaft Timing and proper sequential fuel injection. So yes, a camshaft sensor is used and it’s critical to how the Focus runs.

The camshaft sensor feeds the PCM a precise cam position signal so the engine can sync fuel injection and spark, juggle valve timing on Ti‑VCT engines, and keep cold starts clean. It’s a Hall‑effect sensor with a 5‑volt reference, ground and signal, reading a toothed target on the cam. If its signal drops out or goes flaky, the engine has to guess cam timing from the crank sensor, which is why driveability can go pear‑shaped.

Tell‑tale signs of a crook CMP on a 2011 Focus include:

• Hard starting, rough idle, flat spots, or stalling once warm
• Sluggish performance and higher fuel use
• Check Engine Light with codes like P0340/P0341
• Occasional limp‑home mode on Ti‑VCT engines

Servicing advice: the sensor itself isn’t a scheduled replacement item, but it should be checked whenever there are timing or misfire faults. Under the bonnet it lives at the end of the cylinder head (top front or rear depending on engine), usually under the plastic engine cover. Inspect the connector for oil intrusion or broken locking tabs, and make sure the harness hasn’t rubbed through on the cam cover.

Replacement is straightforward for most engines: disconnect the battery negative, remove the engine cover, unplug the connector, undo the retaining bolt, and wiggle the sensor out (there’s an O‑ring). Lightly oil the new O‑ring, seat the new sensor cleanly, and tighten the bolt to the workshop‑manual spec. Clear codes, then verify live data and a clean cam/crank sync on a scan tool. If faults return, don’t forget to check for timing chain stretch, contaminated reluctor targets, or wiring issues — the sensor is only one piece of the cam timing puzzle.

For parts, stick with genuine Motorcraft or a quality equivalent and replace the O‑ring with the sensor to prevent weeping. A quick road test after fitting will confirm VCT responds crisply without hesitation.

Popular questions

Where is the camshaft sensor on a 2011 Ford Focus?
It’s mounted on the cylinder head near the camshaft end, typically at the front of the engine under the plastic cover on the petrol models, and accessible from the top on most variants. Some engines have two sensors — one for intake and one for exhaust.

Do camshaft sensors need regular replacement?
No set interval. They’re replaced on condition. During routine servicing, inspect the connector and loom, check for stored cam/crank correlation codes, and address oil leaks that can contaminate the plug. If symptoms or fault codes point to the CMP, test it before replacing.

Is it safe to drive with a bad camshaft sensor?
It may run, but starting can be hit‑and‑miss and the engine can drop into limp mode. Prolonged driving with poor sync can affect fuel economy and emissions, and it can mask timing chain or VCT issues. Best to diagnose and fix promptly.